The prior art contains many patents and teachings of explosively actuated energy transferral "cords" which operate either:
(1) in the mode of a "fuse", a relatively slow-moving containment of explosive composition encased within a wrapping, the "burning" of which fuse transfers energy to initiate an explosive in a remote location, or (2) a detonating fuse, constituting a core of explosive encased within a wrapping, ignition of which initiates a relatively fast-moving linear explosion which, in turn, initiates a remote charge which may be utilized to produce a desired work function.
In the early 1970's, in an effort to reduce weight and costs, and to simplify an improved product, it was proposed to utilize a "fuse" containing only a very small amount of explosive material placed in a very thin layer on the inner portion of a cord or tube. An example of this "thin-layered explosive" is contained in U.S. Pat. No. 3,590,739 issued to Persson on July 6, 1971. Briefly, this patent utilized a very thin layer of PETN, RDX, or HMX explosive materials on the internal surface of a tubular cord, the ignition of which material caused the creation of a shockwave of energy which was perpetuated down through the cord, at the end of which a larger explosive charge was initiated to accomplish a desired function. The Persson patent suggests that the otherwise hollow core may contain, either as an integral part of the surrounding sheath or as a separate member, a support member which extends longitudinally through the tubular chamber.
An earlier U.S. Pat. issued to Hicks in 1964, i.e., No. 3,125,024 shows an explosive cord contained within a multi-layered sheath, the explosive content of which, compared to TLX, is relatively heavy.
U.S. Pat. No. 4,220,087 issued Sept. 2, 1980, to Posson shows a thin-layered explosive on the inside of a containing sheath and which is also provided with one or more "strands" of explosive which may contain supporting wires or strands extending longitudinally through the core of the structure.